There have been known oily cosmetics comprising vegetable oils, mineral type oils or mixtures thereof. For example, oily cosmetics containing olive oil, mineral oils or camellia oil have been widely employed for preventing the skin or hair from drying and for moistening the same. In particular, olive oil has been frequently used in Western countries for maintaining the smoothness of the skin or preventing the skin from drying. Immediately after applying olive oil to the skin, however, the skin surface becomes oily and, therefore, miscellaneous bacteria in the air would stick thereon more frequently than the ordinary state. Thus, it is feared that such skin surface might serve as an adequate medium for the growth of the miscellaneous bacteria.
To solve this problem, it has been a practice to add antibacterial compounds to oily cosmetics. However, a large number of artificially synthesized chemicals sometimes cause eczema and skin fit in consumers highly sensitive to chemicals, which makes it necessary to use these oily cosmetics with care. Actually, most of these products are marketed in association with strict instructions.
It is an object of the present invention to provide oily cosmetics which are free from the above problem and thus can be safely used even by consumers highly sensitive to chemicals. This object can be achieved by providing oily cosmetics containing tea leaf components which are natural materials and a process for producing the same. The term “oily cosmetics” as used herein means cosmetics to be applied to the skin such as oily liniments or oily hair care products such as hair oils.
In addition to β-carotene, tocopherol (vitamin E), ascorbic acid, niacin, etc., tea leaves contain substances having purine base such as caffeine and essential oil components such as geraniol. Moreover, it is already known that tea leaves contain various tannins in a large amount. Among all, it is known that much catechins falling within the category called fused tannins are contained therein. As the results of recent studies on effects of catechins contained in tea leaves, it is reported that catechins have a bactericidal and antibacterial effect, a deodorizing effect, an effect of preventing atopic dermatitis, a hypotensive effect and the like.
Since catechins are soluble in water, a special treatment is required to dissolve a sufficient amount of catechins in an oily base (Japanese Patent Publication of unexamined Application No.279758/1994). There have been known cosmetics containing tea extract, for example, cosmetic oils obtained by blending tea extract and vitamin E to linoleic acid (Japanese Patent Publication of unexamined Application No. 78231/1993), cosmetics obtained by blending tea extract, disodium ethylenediaminetetraacetate, etc. with lipids containing highly unsaturated fatty acids such as linolenic acid (Japanese Patent Publication of unexamined Application No. 81325/1996), and antibacterial cosmetic compositions comprising as the essential components tea extract containing catechins, tea tree and thyme extract (Japanese Patent Publication of unexamined Application No. 63262/2000). However, there has been known no cosmetic comprising tea extract alone without any other active components.
The present invention aims at producing and providing oily cosmetics which have excellent properties including antibacterial activity and are mild to the skin by totally using various active components typified by catechins contained in tea leaves without resort to any chemicals such as emulsifiers.